This revised SBIR Phase II application proposes to further develop a non- invasive self-contained portable system to efficiently test individuals daily to detect impairment related to alcohol use, and thereby decrease the risk of accidents and health problems related to alcohol use. There are unresolved social and legal issues, but this approach produces less infringement on civil liberties than urine or blood tests. The portable testing units will measure vigilance attention, reaction time, and pattern recognition and prediction performance. Impairment in these neurocognitive functions is a major reason for increased accident risk from alcohol misuse and abuse in the workplace. Efficient detection of impairment would produce benefits for society, both in human and economic costs. Economic costs are estimated to be $8O billion per year in the United States, so that even a relatively small reduction in accident rates would be worthwhile. This SBIR Phase II project will achieve goals critical for commercialization of the product. First, the portable testing unit will be further refined and made more durable for at-home subject testing. Additional performance parameters for pattern recognition and prediction will be acquired. A small scale manufacturing operation will be set up to develop 30 new units and software needed for the Phase II studies. This limited manufacturing effort will provide experience for progression to larger production efforts in the future. These units will be marketable to researchers after completion of the Phase II research. Second, daily, in-home baseline testing over a 7-week period will be completed on 128 subjects. A brief automated Health Behavior Questionnaire will be presented by the device for subjects to complete a daily report of alcohol consumption, smoking behavior, caffeine use, sleep patterns, general health, etc. We will examine the psychometrics of the test for detection of impairment under naturalistic conditions. Third, laboratory studies will examine the interaction of alcohol and two widely used drugs (nicotine and caffeine) which may alter test sensitivity. The effects of nicotine and caffeine will be examined on the ascending limb, at steady state, and on the descending limb of the blood alcohol curve, and the morning after the drinking session. These data will be critical for determining the ability of commonly used substances to alter the sensitivity and specificity of alcohol impairment detection by the testing device. Across baseline and laboratory testing, two potentially important subject characteristics, gender and alcohol consumption level (light to moderate vs. heavy), will be examined as moderators of test sensitivity. These Phase II activities will establish a product for the research market, and a basis for subsequent workplace commercialization of the product. PROPOSED COMMERCIAL APPLICATION: Commercial potential includes research use as well as in occupational settings where accidents are significant problems. The testing unit has the potential to be integrated into transportation and other heavy equipment to prevent operation unless the operator can demonstrate absence of impairment. Motor vehicle departments could use the system to screen applicants for drivers licenses, and record individual baseline data for use by highway patrol officers.